The present invention relates to a monitor system of a beam position in an irradiation system of a charged particle beam (particle beam, ion beam), and more particularly to a beam monitor system in a particle beam irradiation system suitably applied to a particle beam therapy device that irradiates an affected area with a particle beam such as protons or carbon ions for treatment.
A treatment method has been known which irradiates an affected area of a patient suffering from cancer with an ionized particle beam such as protons or carbon ions. An ionized particle beam irradiation system (particle beam extraction device or ionized particle beam extraction device) used for the treatment includes an ionized particle accelerator. An ion beam accelerated by the ionized particle accelerator reaches an irradiation device installed in a rotating gantry through a first beam transportation system and a second beam transportation system disposed in the rotating gantry. The ion beam is extracted from an irradiation device, and exposed to the affected area of the patient.
As irradiation systems of the irradiation device, there have been known, for example, a double scattering system (p. 2081, FIG. 35 of “REVIEW OF SCIENTIFIC INSTRUMENTS, VOLUME. 64, NUMBER 8, (August 1993), P2074-2093”) that scatters a beam by a scatterer, and broaches the beam into an affected area shape as disclosed in “REVIEW OF SCIENTIFIC INSTRUMENTS, VOLUME. 64, NUMBER 8, (August 1993), P2074-2093”, a wobbler method (p. 2084, FIG. 41 of “REVIEW OF SCIENTIFIC INSTRUMENTS, VOLUME. 64, NUMBER 8, (August 1993), P2074-2093”, and a scanning system (pp. 2092 and 2093 of “REVIEW OF SCIENTIFIC INSTRUMENTS, VOLUME. 64, NUMBER 8, (August 1993), P2074-2093”) that scans the affected area with a fine beam.